East Fork Lewis River Habitat Enhancement

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The Lower Columbia Salmon Recovery Plan lists all East Fork Lewis River (EFLR) salmon populations as primary, making it one of the most important watersheds for salmon recovery efforts in the Lower Columbia River System. Clark County Public Works hired ESA to provide assessment, feasibility, and design services for a series of aquatic habitat enhancement projects along a 1½-mile-long reach of the EFLR.

ESA reviewed five conceptual projects identified in the Lower EFLR Habitat Restoration Plan.  We performed field investigations of channel cross-sections, channel profiles, habitat features, and vegetation that supported concept-level (30 percent) designs. The designs were presented to County Public Works staff, Legacy Lands staff, the Lower Columbia Fish Recovery Board (LCFRB), and the LCFRB Technical Advisory Committee.  Designs considered habitat benefits, effects on park infrastructure, cost, and potential maintenance requirements.  The committee selected two projects to take forward to preliminary (75 percent) design.  One design expanded an existing alcove downstream of the Lewisville Park boat launch, and the other improved access to the outlet of the existing side channel just upstream of the SR 503 bridge.

Following ESA’s work for the Lewisville Park sites, we developed preliminary designs for two sites at Upper Daybreak Park (EF-16 and EF-20). To guide design efforts, staff installed groundwater monitoring wells at each site to evaluate the effect of hyporheic flow and groundwater on off-channel features. We ensured the preliminary project designs, specifications, and cost estimates provided a detailed understanding so that the projects would be competitive for grant funding.  We updated a FEMA HEC-RAS model to evaluate design impacts for floodplain permitting.

Both the EF-20 and EF-16 projects were selected for grant funding by LCFRB.  The final designs for these sites used excavation combined with the placement of large wood structures to create self-maintaining rearing and spawning habitat that is accessible to fish during low summer flows. Construction was completed during the summer of 2013 for the EF-16 site and in 2014 for the EF-20 site.

ESA’s restoration designs benefit federally listed threatened steelhead, Chinook, coho, and chum salmon by increasing and enhancing off-channel rearing habitat, as well as mainstem rearing and spawning habitat.

Specialized Services

  • Channel and floodplain restoration design
  • Construction observation and support
  • Design specifications and construction bid packages
  • Engineering design and construction documents
  • Fish passage design
  • Grade control and bank stabilization
  • Habitat restoration and enhancement
  • Hydrologic and hydraulic modeling
  • Large woody debris and in stream structures
  • Modeling and analysis
  • Monitoring
  • Native plant revegetation
  • Post-construction monitoring